Take-up device



June 16, 1936. H. JWSTEGEMAN 2,044,719

TAKE-UP DEVI CE Original Filed April 21, 1954 v INVENTOR.

W Y I BY 77 ATTo11vE?s.

Patented June 16, 1936 TAKE-UP DEVICE Henry J. Stegeman, Fairfield;Conn., assignor to lhe Locke- Steel Chain Company, Bridgeport, Conn, acorporation of Connecticut Original application April 21, 1934, SerialNo.

721,759. .Divided and this application :November 19, 1934, Serial No.753,660

10, Claims.

This application is. a division of my copending application Ser. No.721,759. The novel features of. the .inventioridisclosed andclaimedherein bebest understood from the following de- 5 :1. scriptionand the annexed drawing, in which] have shown a selected embodiment'ofthe inven- 1 tion and in which:

1. is. an enlarged View of a slack take-up -;device;

Fig. 2 :is a plan view of the structure appearing 5.111 Fig. 1;

Eig.i3 is a view, partly in elevationand partly dmsection, .taken' fromthe right of Fig. 1.

i-The invention is shown as applied to amow- -ing machine of the generaltype disclosed in-my ecopending' application Ser. No. 634,485, althoughof course, it may be applied to other machines awhere found suitable,that is, wherever one shaft :sis driven from another by means of aflexible tdrivingrelement, suchasa chain or belt.

:In thisparticular embodiment, the .chain- 68 is shown as connecting adriving sprocket 69 -and a .driven sprocket l and as having a tight".side. 'lllandzxa slack side". ;The tightside is, 9, of course, the.driven side underxnormal condi- ,tions, for example, when thezchaingismoving. in the direction indicated by the; arrow .13. The two 1:sprockets 69and 'IOmay be journaled in anysuit- :rablebearings (not:shown) .on the frame. I. of;the

Pivotal1y mounted on the iframe, asatfld, is .an .-arm 15 having at theupper end thereof a trans- .versely extending stud 'lfi'which forms apivot -\;for. the idler roll TI. The rollis held .inyielding5..engagement with the slack side 12 of the" chain by a tension springlazengagingrthe armrl and a [fixed part 19of the frame,in thisform'lthispart vbeing an upwardly extending, projection on"v the frame.The arrangement just described serves to t aotprevent whipping of thechain to a certain extent n and-also to make the chain hug thesprocketsat all etimes.

Theprojection 19 has in-the .upper portion .thereof a hole 80' having aconically shaped wall,

4.45and extending through this hole is a rod 8lhaving a head82 betweenwhichand theprojection l Us a compression spring 83. Extending throughthe rod 8|; on the other side" of the projection .from the spring 83 isa cotter pin 84 which-limits 50 movement-ofthe rod 8 I, under action ofthespring 83, by engagement with theprojection or stop 19.

:Between the arm and theroll ll is a spac- .ing=sleeve=.=85,rand' therod 8| passes above the ;sleeve-. between the 1 arm and the roll, asplainly 2:15 .shown inthe-drawing,

Also disposed between the arm 15 and the roll 11. is a U.-shaped yoke 86having in its two' legs .18! and. 88 aligned holes through which the rod:8]. may pass.

Disposed above the sleeve 85 is arlock in the form of a locking dog 89havinga hole through which the rod.8l passes, and between this dog andthe upper leg'88' of the yoke 915 a. relatively light compression spring90 tending -to.:urge thezdog against the-sleeve 85.

.J'I'he initial position of the roll "is. shown in full lines in Figs. 1and 2, and the initial position .of. the chain 12 is shown in dot anddash lines in: Fig. 1.

In ordinary operation, the tendency ofthe spring 18 1s towns: the rollTI to take up i the ordinaryslack in. the side12 of the. chain-l5weanmayoccur, thesleeve 85bearing against the :lowerzleg 81 of theyokewill move this yoke Movement of the rod itself because of. itsengagement with the. leg. 88 of the sleeveiflli. This spring willincline the'dog so that l .the rod will pass through the hole in thedogat 1 yoke, will followthe .movement of that yoke and keep theidogd89 inclose engagement with the such an angle asto-"cause the dog to bind .on

the rod and resist any. tendency of the-dog. to

1 move upwardly or to the right of Fig. 1 along the ':rod. ..The abovearrangement would be sufficient if all the hearings were rigidly fixedwith respect to each other.

i'j-Whenioranyreasonphowever, an excessive loadisapplied to the tightside ll of the chain,

the elasticity of the chain, shafts, bearings, and

. other parts will permit an excess of slack on the side 12 of thechain, which permits the roll 11 and parts associated therewith to movetoward the leftnofrFig. 1 to some such positionas that .shown indottedlines in Fig. 1, the yoke and locking dog sliding along the rod 8|,which is still held against such movement by engagement of the cotterpin.84 "with the stop 18. When such excessive load is removed, then theelasticityof the various parts will. tend to cause them. to 5 .resumetheir normal positions, includinga return of the side '12 of the chainto the position shown in dot anddash lines in'Fig. 1.

'iThisjreturn of the side' 'l2 of the chain is resisted bylthe roller'll whichis locked in positionvby the locking dog!!!) on rod 8!.

To'permit the chaintobe' restored to its normal. position,

:therod 8 ll mayslide through the hclein' the stop 19,1. andvthespringf83. is" weak enough "to. permit ::,this.:movement,1buti the.coils of the. spring will come in contact with each other and will forma positive stop by the time the side 12 of the chain has reached itsnormal position, such as indicated, for example, in dot and dash linesin Fig. 1, and until the cotter pin 84 and head 82 have reached somesuch position as shown in full lines in Fig. 1. As another excessiveload is applied, the rod 8| may move to the left until the pin 84engages the stop 19, and as succeeding excessive loads are applied andreleased, the rod' may move back and forth between the positions shownin full and in dotted lines in Fig. 1. The spring 83 normally will movethe rod before the yoke will slide along the rod, and, until the cotterpin 84 strikes the stop 19, all natural wear will be taken up by actionof the spring 83.

Preferably, this spring 83, here shown as a fiat coil spring, is of sucha kind as to exert a substantially uniform action throughout itscompression, as nearly as that can be done by any spring, and the lengthof the'spring should be such that'the difference between its free lengthand its compressed length will correspond to the difference betweennormal position and maximum loaded position of the chain; in otherwords, between the positions indicated roughly by dot and dash and bydotted lines in Fig. 1.

In case of a reversal so that the side 12 of the chain becomes a drivingor tight side, the coils of the spring 83 likewise come together and.act as a positive stop to prevent excessive movement of the rod Bl tothe right, which would create an excess slack in the chain, particularlyon the side H which is not provided with a takeup roller. It will alsoprevent the chain loosening on the sprockets because of any excessslack.

The above arrangement has a;material advantage over one in which asingle spring, such as the spring 18, is. used, because if such a springwere relied upon to perform the same action as that for which the spring83 is used, there would be a continual flutter of the roller 11, whichwould be undesirable, and moreover the spring 18 would have to be sostrong that it would tend to cause binding of the chain on thesprockets. By the arrangement described above, however, the spring 18may be used merely to follow up the wear in the chain.

The conical shaped wall 80 permits the rod 8| to pivot in the projection19 as the roll moves t the right or to the left of Fig. 1.

While I have shown the invention as embodied in a specific form, it isto be understood that various changes in details may be made withoutdeparting from the scope of the invention, and I therefore do not intendto limit myself except by the appended claims.

I claim:

1. A slack take-up device for a chain or belt comprising a roller,adapted to engage the slack side of a chain, a fixed frame, an armpivoted on said frame and carrying said roller, a spring holding saidroller in engagement with said chain, an auxiliary compression springacting in the same direction as said first-named spring and also tendingto hold said roller in engagement with the slack side of said chain, anda stop limiting expansion of said auxiliary spring.

2. A slack take-up device for a chain or belt comprising a rolleradapted to engage the slack side of a chain, a fixed frame, an armpivoted on said frame and carrying said roller, a spring holding saidroller in engagement with said chain, an auxiliary compression springacting in the same direction as said first-named spring and also towardsthe chain;

tending to hold said roller in engagement with the slack side of saidchain, said compression spring having coils adapted to contact with eachother to form a positive stop, and a stop limiting expansion of saidauxiliary spring.

3. A slack take-up device for a chain or belt comprising a rolleradapted to engage the slack side of a chain, a rod extendingtransversely to the direction of movement of said slack side of thechain, a locking dog slidably mounted on said rod and engaging saidroller to prevent movement thereof away from the chain while permittingthe roller to follow the chain as it wears, means slidably supportingsaid rod, means limiting the movement of said rod in the direction ofmovement of the roller as it takes up slack, and a spring yieldinglyresisting movement of the rod in the opposite direction from reaction toexcessive loads.

4. A slack take-up device for a chain or belt comprising a rolleradapted to engage the slack side of a chain, a rod extendingtransversely to the direction of movement of said slack side. of thechain, a locking dog slidably mounted on said rod and engaging saidroller to prevent movement 7 thereof away from the chain whilepermitting the roller to follow the chain as it wears, means slidablysupporting said rod, means limiting the movement of said rod in thedirection of movement of the roller. as it takes up slack, and a springyieldingly resisting movement of the rod in the opposite direction fromreaction to excessive loads, the difference between thefree conditionand the loaded condition of said spring corresponding to the differencebetween the normal position andthe excessively loaded position of thechain.

5. A slack take-up device comprising a roller adapted to engage theslack side of a chain,'a support for said roller movable towards andaway from said chain, a spring urging said support towards the chain tohold said roller in engagement with said slack side thereof, a lockpreventing movement of the roller away from the chain, and an auxiliaryspring acting upon the roller through said lock to likewise urge theroller 6. A slack take-up device comprising a roller adapted to engagethe slack side of a chain, a support for said roller movable towards andaway from said chain, a spring urging said support towards the chain tohold said roller in engagement with said slack side thereof, a lockpreventing movement of the roller away from the chain, an auxiliaryspring acting upon the roller through said lock to likewise urge theroller towards the chain, and means limiting the movement of the. rollertowards the chain under the influence of said auxiliary spring.

'7. Aslack take-up device comprising a roller adapted to engage theslack side of a chain, a support for said roller movable towards andawayfrom said chain, a springurging said support towards the chain to holdsaid roller in engagement with said slack side thereof, a lockpreventing movement of the roller away from the chain, an auxiliaryspring acting upon the roller through said lock to likewise urge theroller towards the chain, and means limiting the movement' of the'rolleraway from the chain as said" auxiliary spring yields. I

8. A slack take-up device comprising a roller adapted to engage theslack side of achain, a support for said roller movable towards and awayfrom said chain, a spring urging' said sup-' port towards the chain tohold said roller in engagement with said slack side thereof, a lockpreventing movement of the roller away from the chain, an auxiliaryspring acting upon the roller through said lock to likewise urgetheroller towards the chain, means limiting the movement of the rollertowards the chain under the influence of said auxiliary spring, andmeans limiting the movement of the roller away from the chain as saidauxiliary spring yields.

9. A slack take-up device comprising a roller adapted to engage theslack side of a chain, a

support for said roller movable towards and away sponding to thedifference between normal and maximumpositions of said slack side of thechain.

10. A slack take-up device comprising a roller adapted to engage theslack side of a chain, a

'suport for said roller movable towards and away from said chain, aspring urging said support towards the chain to hold said roller inengagement with said slack side thereof an auxiliary relatively weakcompression spring also acting upon said roller to urge it towards thechain, said auxiliary spring acting between relatively fixed and movableparts and the difierence between its free and compressed lengthscorresponding to the difference between normal and maximum positions ofsaid slack side of the chain,

, and means limiting the movement of the roller towards the chain underthe influence of said auxiliary spring.

HENRY J. STEGEMAN.

